Air conditioning systems are conventionally provided within buildings using either sheet metal ducting or flexible duct systems. Sheet metal ducting provides rigid metal ducts which may be laid-out and installed in tidy configurations and which are not easily subject to movement. However, sheet metal ducting is typically more expensive and time consuming for installation, requiring more detailed engineering and labor to specify sizes and lengths for ducts, providing inventory of ducts of particular sizes, cutting ducts to particular length during installation, and to install rigid sections of metal duct. On the other hand, flexible duct systems are much less engineering and labor intensive, with the flexible ducting readily adaptable into various installations. Flexible duct is readily cut to length during installation and each section does not have to be specifically manufactured for a particular size as does formed metal ducting. However, flexible metal duct is not tidy when installed. Since flexible duct is not rigid, it sags or droops between end connections and is typically laid in a crawl space or attic, directly on the floor of such spaces. Connections of multiple flex duct to a primary plenum typically appear much more like a spaghetti jumble rather than the clean configuration of rigid metal ducting after installation.